I don't like this move, as I don't see how it helps White's plan.
15... e6d5  16. c4d5  16... e7d6  17. d3c2 It's hard to break Black's position, but White can try for a long time without much risk (although in a blitz game there is always some risk). The plan is to push f2-f4 at the right moment. 17... d8c7 